Adsorptive investigation on heavy metal removal from aqueous solution using surface treated cassia fistula seeds

Abstract

newline Globally, large portion of water environment is being contaminated and destroyed due to the direct liberation of industrial effluents, agricultural and municipal activities. The contaminated water has several toxic pollutants which becomes carcinogenic to humans, plants and animals, comparatively has a higher density, accumulation in the water and biodegradability. Amongst the several pollutants, heavy metals are considered to be serious hazard throughout the world. These heavy metals originate from different sources such as industrial effluent discharge, sewage disposal, and anthropogenic processes. Diverse metal ions such as chromium, zinc, lead, nickel, cadmium, mercury, copper and arsenic are synthetically moving into the water streams and causes adverse effects to the ecosystem. Industries are the huge source of water pollution which includes dairy, refinery, sugar mills, electroplating, textile, paper mills, automobile, fertilizer, mining, petroleum, dyeing, leather, printing, pulp, brewery, aircraft, gas, pesticides, plastic, battery, tannery, construction, photography and metal, etc., it produces pollutants that are extremely harmful to people and the environment. Raw industrial effluents possess higher concentration of organic contaminants which directly disposed with high salinity is a cumulative risk in worldwide. Several industrial facilities utilize freshwater for several purposes such as fabrication, washing, processing, cooling, dissolving and diluting. The utilized water from the plant can be returned as effluents to the water region (rivers, lakes and oceans) which consists of heavy metals, dyes and other toxic wastes. Water plays a significant role for human metabolic process primarily in the breakdowns of large substances into smaller substances. The discharge of toxic pollutants has a negative effect on water environment which becomes serious issue to the humans, plant and aquatic life. The presence of contaminants in the surface and groundwater could directly been used for human consumption which in turn causes hazardous health effects such as borne disease, dermatitis, dysentery, jaundice, cholera, lung disease, typhoid, skin irritation, kidney, diarrhoea, headache, gastroenteritis, immunity disease, vomiting, liver illness, respiratory problem, neurological effects and anaemia. The continuous discharge of toxic pollutants into the water leads to accumulation and hence increases the concentration of pollutants. This occurrence poses a serious environmental threat and water scarcity, therefore different conventional treatment methodologies have been employed for wastewater treatment newline newline